The circled part is the "translucent" part. Its the yellowish looking part at the very tip of the shell. You can actually see the new shell underneath, and im surprised to see its growing inferiorly to the old part.
It looks like the shell is chipped where the arrow is pointing, but its only part of the old "translucent" part that is falling off. As you can see below, right above the blue lines, you can see the new scute underneath. It is perfectly rounded. At first I freaked out and thought she chipped her shell, but that part just fell off. She may have chipped that old part, but it was bound to fall off anyways.
Here is a pic of more scutes. The yellowish part are also starting to become translucent, and this corresponds with what steve is saying about the translucent shell being superior and inferior. Notice where the "outer" scutes meet the "middle" scutes. Its starting to turn a good dark brown. This was the first to shed, before any scutes, and it was a whitish color. I was nervous at first seeing this, I thought that she was banging her shell, and it almost looked like that part was sorta chipping (hard to describe).. but I am now happy with the results!I am pleased to see the BEAUTIFUL colors coming in on my baby.
She looks very healthy and a little camera shy 
